Make it easier to create builders with pluggable naming conventions

[seancorfield]

See https://clojureverse.org/t/next-jdbc-1-0-0-beta-1/4307/3

It would be nice if there were a generic get-pluggable-column-names that accepted a string-based naming strategy and/or a generic builder that accepted such (and handled the column name strategy directly).

Perhaps then rewrite the lower variants in terms of that?

Need to consider qualified/unqualified variants of it too.

[seancorfield]

get-modified-column-names, get-unqualified-modified-column-names, and all the matching as-*-(maps|arrays) variants too.

Rewrote lower variants in terms of those. Also updated next.jdbc.optional builders.